Present-day exhaust-gas recirculation systems (EGR) are typically controlled via an electronic injection device, a control unit (ECU) being provided for this purpose on the internal combustion engine. The EGR volume is controlled via a characteristic map which corresponds to the load states of the internal combustion engine.
Electronics or ECUs of this kind are entirely lacking in today's “mechanical” internal combustion engines which come equipped with an in-line injection pump. The only load signal present in these “mechanical” internal combustion engines is that which indicates the position of the control rod at the injection pump.
The German Patent DE 199 12 317 C2 describes an internal combustion engine, an EGR valve (exhaust gas recirculation valve) being located in the exhaust-gas recirculation line. An electronic control device is provided for controlling this EGR valve.